Technological advancements in mobile computing devices have changed the way people use computers and access the Internet. It is no longer commonplace for a typical user to have only a primary home computer and possibly a work computer. Instead, the typical user uses multiple computing devices, one of which is often a mobile or handheld device such as a smartphone or a tablet computer. With respect to Internet-based advertising, the use of multiple devices by a single user means that Internet-based advertisers cannot maximize personalized advertising performance by simply using a single browser cookie as a reasonable proxy for a user. Rather, in order to build comprehensive and rich user profiles, Internet-based advertisers need to look at user activity across several devices. In addition, there are increasingly fewer opportunities to identify users and track user activity through logins since a user's need to constantly login to a personal account in order to access information has decreased, especially for mobile devices and mobile applications running on mobile devices.
Since computing devices are increasingly used by a single user and not shared among several users, identifying a particular physical device for purposes of Internet-based advertising may be desirable. The task then becomes how to identify a physical device. Identifying physical devices through a network address, such as an Internet Protocol (IP) address, may not be desirable since multiple devices used by different users may be connected to the same network or otherwise have the same IP address.
One way to identify users is through device identifiers (IDs) that are integrated with web browsers and applications (e.g., mobile applications). However, currently, web browsers and applications use different device ID types or formats. As a result, a web browser and an application running on the same physical device provide different device IDs when accessing the Internet. Consequently, tracking systems that track device IDs in order to monitor user activity do not know if device IDs of different types belong to the same physical device or different physical devices. In turn, profile builders that build user profiles may create multiple, unassociated user profiles instead of one combined profile for a single device. Additionally, Internet-based advertisers or other users of the user profiles may miss opportunities to leverage already-learned information about a user because different device IDs for the same device were not linked together. As such, ways to assess or identify whether different-type device IDs belong to the same physical device may be desirable.